The current is detected by using a shunt resistor, which measures a voltage caused by the current flowing through the shunt resistor in various kinds of current detections. The detection includes, an electrical charge and discharge current in a battery, a motor current that drives an electric vehicle or a hybrid-power car etc., a current in electric equipment such as air conditioner, and a current in power generation machines including solar battery etc.
Conventionally, a shunt resistor and a bus bar is connected by forming holes in an electrode portion of the shunt resistor and a portion of the bus bar, and fixing the shunt resistor and the bus bar by inserting a bolt through the holes of the shunt resistor and the bus bar and screw fastening the bolt to a nut. Also, making an electrode portion of a shunt resistor to be a bolt-like portion, inserting the bolt-like portion into a hole in a bus bar, and screw fastening a nut onto the bolt like portion of the shunt resistor is known (for example, Japanese re-open intentional patent publication WO2011-68205).
However, according to such connections between the busbar and the shunt resistor, because of increase of connections, a heat generation occurs by contact resistance at the connection between the busbar and the shunt resistor, and a problem of securing connection reliability occurs. Then, a current detection device that can be used for detecting a large current with high reliability is required. Japanese laid open patent publication 2008-039571 discloses a bus bar type shunt resistor, which includes a first wiring member, a second wiring member, and a resistor body welded and fixed between the first and the second wiring members, and which is formed like a bus bar (see FIG. 6 etc.).